Mystery Windows Phone: Nokia Lumia 800 or something else?

We have a little discussion going on amongst the WPCentral writers concerning the Windows Phone used in Microsoft's Hotmail advertisement. At first we thought it could be the HTC Titan until we noticed the Nokia apps (Drive, Maps, and Music).

We now have two schools of thought. One side of the coin has this being the Nokia Lumia 800 and the actress has small hands (hobbit hands was the description actually used). The mystery device appears to share the 800's buttons and silver strip on the back.

The other side of the coin calls for this to be a new Nokia, maybe the Lumia 900? Should the actress have average hands, the screen appears to be much larger than the Lumia 800 and the backing seems more gray than black.

So, what do you guys and gals think? Lumia 800, 900 or something else?